Privacy

Free-tier diffs

Free diffs are computed in your browser. The text you paste into the Before / After fields does not leave your machine unless you explicitly opt into the AI summary.

AI summary

When you tick "Summarize this change", the text is sent to OpenRouter (anthropic/claude-haiku-4.5) for a one-shot summarization request and discarded after the response. We do not retain free-tier text. Don't paste secrets, tokens, or anything that shouldn't traverse a third-party LLM.

Saved diffs (Pro)

Pro users explicitly press Save & share to persist a diff. The Before / After text is stored in our database, indexed only by an opaque ID. Each diff has an unguessable 16-hex view token; only people with the share URL (or you, signed in) can view it. Pages are noindex and never appear in search engines.

You can delete a saved diff at any time from your dashboard. Deletion is immediate and removes the row from our database.

Account & billing

Sign-in is centralized at account.basenull.com. diff verifies your session via a shared cookie; we don't issue our own. Subscription billing runs through Stripe — we never see your card.

Cookies & analytics

We set the shared bn_session cookie when you sign in. We use Umami Cloud for privacy-preserving page analytics (no personal data, no cross-site tracking).

Contact

Questions: hello@basenull.com.